* Set call parameters - advanced and not recommended feature - use with caution.
* Local call parameters applicable to an outgoing or incoming shall usually be passed to linphone_core_invite_address_with_params() or
* linphone_call_accept_with_params().
* However, in some cases it might be desirable from a software design standpoint to modify local parameters outside of the application layer, typically
* in the purpose of implementing a custom logic including special headers in INVITE or 200Ok requests, driven by a call_state_changed listener method.
* This function accepts to assign a new LinphoneCallParams only in LinphoneCallOutgoingInit and LinphoneCallIncomingReceived states.
* Returns local parameters associated with the call.
* This is typically the parameters passed at call initiation to linphone_core_invite_address_with_params() or linphone_call_accept_with_params(), or some default
* parameters if no LinphoneCallParams was explicitely passed during call initiation.